Successful mandibular complete denture therapy relies on adequate denture retention and stability from the residual alveolar ridge. Denture retention influences a patient's ability to function and, if adequate, affords the patient confidence and comfort. Unfortunately failure to achieve adequate retention and stability may be due to factors not influenced by appropriate complete denture therapy alone. A new treatment modality providing magnetic retention between the mandibular complete denture and implants placed within the mandible, shows promise as a predictable and cost effective method of increasing denture retention. To date, no controlled clinical studies have been reported regarding this treatment. The purpose of this investigation is to complete a clinical study of the magnetically retained mandibular overdenture utilizing osseointegrated implants. The study will specifically (1) quantify clinical difference in retention and stability between conventional attachment retained dentures and the magnetically retained overdenture; (2) identify change which may occur in the supporting tissues; (3) monitor patient satisfaction with each treatment modality; and (4) document failures of material and/or methods. Additionally, it will be possible to see if a correlation exists between variables. Twenty healthy edentulous patients will be studied. Each will have one implant placed in the mandibular canine region bilaterally. After successful implant osseointegration, the patients will be randomly divided into two groups of ten. Using a crossover experimental design, each group will receive either magnetic or O-Ring denture retention for six months and then will be switched to the other attachment for an additional six month period. Quantitative analysis of retention and stability of the dentures before and after incorporation of attachment retention will be accomplished by measuring the force of denture dislodgement with a force gauge. Additionally, retention, stability and tissue response will be measured using criteria established to describe a range of possible conditions. Investigators will match the patient's condition to the best corresponding criteria and a scoring system will allow comparison between patients. Patients will also indicate denture satisfaction before and after attachment retention utilizing a denture satisfaction questionnaire. Data collection will be accomplished immediately following respective attachment placement and at the end of six months of use. Significant differences in results and correlations between measurements will be established.